Squid is often cooked without removing the skin, which adds to its nutritional value.
Lightly scoring the flesh with a trellis pattern will keep the skin intact and result in a decorative effect when served.

There are about 500 species of squid (or calamari) in the world, but only about 15 to 20 types are suitable for human consumption. Korea′s squid fishing grounds are evenly distributed in waters along the eastern, western and southern coasts. Squid is harvested year-round, but their numbers hit a peak during August through October. These days, commercial vessels are equipped with freezers for storing the catch as soon as it is brought aboard, assuring a steady supply of squid in the marketplace all year round.

Nutritional Value
Squid is a rich source of protein, along with containing trace amounts of vitamins A, E, B1, and B2, as well as niacin, potassium, iron, zinc, and copper. Vitamin E, zinc, and potassium activate cellular function and promote the body′s absorption of iron. The protein content is especially high in dried squid, about three times greater than that of beef. As for its high content of phosphoric acid, this can be offset by serving squid with alkaline vegetables. Some people had avoided squid because it was known to contain 180 milligrams of cholesterol per 100 grams, but more recent research has found that the cholesterol of fish and shellfish is related to the "good" cholesterol, which does not pose a health risk and is actually beneficial for controlling cholesterol levels.
In addition, as compared to other fish and shellfish, squid contains two to three times more taurine, which helps to reduce cholesterol, and 25-60 times more than any kind of meat (327-854 milligrams per 100 grams). When squid is dried, the taurine appears on the surface as a white residue. Squid is low in fat but rich in fatty acids, such as EPA and DHA. It also contains a high content of selenium, which is indispensable for normal cellular function, and also helps to extract toxic elements and prevent the intake of cancerous agents. Moreover, squid ink includes melanin pigment, which is said to deter harmful bacteria and prevent the development of ulcers.

Fresh Squid
Fresh squid has a clear bluish-brown color, protruding eyes, and a transparent, glossy skin. The suckers should be firmly attached to the legs, and the stronger the sucking motion, the fresher they are. Over time, a squid will develop a darkish red color, which indicates that they are not so fresh. Among the popular squid varieties, firefly squid is flavorful in summer while cuttlefish and far eastern arrow squid taste best in the winter. After being caught, squid can live in sea water for two or three days. Live squid has a softer, more pliable flesh after cooking, as compared to a squid that had been flash-frozen at minus 35°C and then thawed out.
Squid is more nutritious when cooked without removing the skin. However, the skin will shrink and can become rather tough after cooking, along with turning a darker color. Usually the skin is left on when the squid is cooked with a dark sauce or when it is stuffed with vegetables or other ingredients. The skin is removed for dishes when clean, light colored flesh is desired. Lightly scoring the flesh with a knife will help to keep the skin intact and result in a decorative effect when served.

Variety of Preparation
Squid can be cooked in a variety of ways. The simplest method is to parboil the squid and eat slices with a dipping sauce of red pepper paste and vinegar. Parboiled squid is tasty with a pleasant firmness. The sauce can be made by combining five tablespoons of red pepper paste (gochujang), with two tablespoons vinegar, one tablespoon sugar, and two tablespoons Sprite.
Another favorite dish is deep fried squid, made by first removing the insides, patting the squid dry, and dredging pieces in a flour batter. The pieces are deep fried in oil and eaten with a soy sauce dip. Fried squid is one of the most popular foods available at street-side stalls, along with tteokbokki, rice cake with red pepper sauce. Roasting live squid whole, with the insides intact, is the most effective way to get the most out of a squid, in terms of tastiness and nutrition. As for a popular version of ojingeo-deopbap, the rice, which is topped with stir-fried squid and sauce, should be cooked with a squid stock for added flavor. However, to simplify the preparation, regular steamed rice can be used.


Ojingeo-deopbap

Ingredients
A. 2 ½ cups rice, a dash of salt
1 teaspoon cooking oil,
⅓ teaspoon sesame oil
B. 1 squid (head, legs),
5 grams kelp, 30 grams anchovies,
1 tablespoon hyangsinjeup*
2 cups water, 1 teaspoon salt
C. 1 squid (body)
30 grams prawns, 1 green chili
10 grams shiitake mushrooms, 20 grams green beans
30 grams eggplant
20 grams onions, 30 grams turmeric
1½ tablespoons cooking oil
1 tablespoon hyangsinjeup
A dash of pepper and salt
D. 1 teaspoon red pepper paste (gochujang)
½ tablespoon fine red pepper powder (gochugaru )
½ tablespoon corn starch, ½ tablespoon soy sauce
½ cup stock made with ingredients from B.
1 tablespoon corn flour, or 1½ tablespoons glutinous rice flour
* (Hyangsinjeup is an extract of various spices and ingredients. Grate radish (200 grams), onion (200 grams), garlic (200 grams), and ginger (10 grams). Squeeze the ingredients and collect the extract. The preparation of hyangsinjeup is optional and can be omitted.)

Preparation
1. Rinse rice and heat in a pan with ingredients from A.
2. Boil together ingredients from B. and then pour liquid through a sieve. Cook the rice with this liquid.
3. Score flesh with trellis marks at 1-centimeter intervals, and parboil.
Cut the cooked squid into thin slices along the diagonal.
Parboil unpeeled prawns, then peel and cut into thin slices.
After removing stalks, slice mushrooms, and marinate in soy sauce.
Cut eggplant into thin slices and lightly season with salt.
Parboil green beans, green chili, and onion, and cut into slices.
Slice turmeric and parboil.
Quickly stir fry ingredients with cooking oil, hyangsinjeup, and salt and pepper, over high heat.
4. Boil together ingredients from D. to make sauce and combine with C. Place the squid and ingredients over the cooked rice and top with sauce.